The present invention generally relates to containers for use in transportation of freight which are capable of being assembled by interlocking connections (hereinafter referred to as "interlockingly-assembled containers"), and more particularly to such an interlockingly-assembled container which is easy to assemble and dissemble by not requiring bolt-fastening connections and is particularly suitable for transportation of component parts and finished products of automobile, motor bike and the like.
When it is necessary to transport, as freight, parts or finished products of automobile or motor bike which are mostly not in the configuration of cube or rectangular parallelepiped, framework-shaped or box-shaped metallic packing containers are conventionally used.
As one form of the above-mentioned packing containers used for transporting automobile or motor bike, there are known packing frameworks which typically comprise a skid forming a bottom frame of the framework, a pair of front and rear end frames positioned on the front and rear ends of the skid, a pair of left and right side frames positioned on the left and right sides of the skid, and top frames interconnecting the front and rear end frames and the left and right side frames. In the past, such packing frameworks were assembled by fastening the parts together by means of bolts at a packing site.
However, since such packing frameworks have a number of bolt-fastening connections, they involve very complex and time-consuming assembly work.
For these reasons, there have been proposed various packing containers from which bolt-fastening connections are removed. For example, Japanese Utility Model Publication No. HEI 4-3953 discloses an interlockingly-assembled transporting container which, as shown in FIG. 15(a), comprises a supporting rail member 7 fixed to the upper edge of four peripheral sides of a bottom frame (not shown), and panel members 9 that are fitted into the rail member 7 to be fixed thereto in an erect or upright position. The supporting rail members 7 include an inner supporting wall 1, an outer locking wall 3 having a height smaller than the wall 1, and a bottom wall 2 continuously interconnecting the walls 1 and 3. (It should be noted that throughout this specification, the term"inner" refers to a "side facing the center of the bottom frame", while the term "outer" refers to a "side facing away from the center of the bottom frame".) The rail member 7 also has a gap provided between an imaginary slope 4 inclining outwardly in contact with at least the upper edge of the wall 1 and another imaginary slope 5 extending in parallel with the slope 4 in contact with at least a part of the locking wall 3. The supporting rail member 7 further has a locking space 6 between the locking wall 3 and the bottom wall. Each of the panel members 9 has at its underside a reinforcing portion 8 comprising a corrugated steel plate which is attached in such a manner that the steel plate is folded inwarly and then outwardly.
Further, Japanese Utility Model Laid-open Publication No. HEI 4-135421 discloses a container employing a metallic connecting structure which is intended for permitting easy assembly and dissembly of the container. The structure, as shown in FIG. 15(b), comprises a rail member including an outside member 11 having a J-shaped cross section, an inside member 12 having a substantially V-shaped cross section and secured to the inside surface of the higher-profile wall of the outside member 11 and a J-shaped-sectional member 13 secured to each panel member. The J-shaped-sectional member 13 has a straight portion continuously connecting to an arcuate-sectional portion. In assembly, the tip end of the arcuate-sectional portion 14 is abutted against the inside surface of a folded portion 15 formed near the distal end of the J-shaped-sectional member 13, and part of the arcuate-sectional portion is held in contact with the inside member 12.
However, of the above-mentioned two packing containers employing a bolt-free connecting structure, the former (i.e., the one disclosed in Japanese Utility Model Publication No. HEI 4-3953) has the problems that the supporting rail and the reinforcing portions of the panel members are fitted with each other in line contact, thus resulting poor connection strength, and that lateral displacement between the supporting rail and the reinforcing portions can not be avoided. With the latter (i.e., the one disclosed in Japanese Utility Model Laid-open Publication No. HEI 4-135421), the connecting structure requires a number of component parts, and it is difficult to determine the respective sizes of the individual component parts and the relative mounting positions of the parts, thus involving very troublesome operations to spot-weld the component parts in place. The latter-said container also can not prevent the relative lateral displacement between the parts.